Hydraulic transmission



Nov. 2, 1937. w. FERRIS ET AL HYDRAULIC TRANSMISSION 7 Sheets-Sheet 1 Filed May 26, 1935 FINVENTURS WALTER FERRIS JAMES K'DUUBLAS GEUREEI H. FUBIAN BYWW ATTEJHNEY- w. FERRIS r-:r AL

HYDRAULIC TRANSMISSION 7 Sheets-Sheet 2 Filed May 26, 1933 @S SRAM E RRLB N mFfwnu Du NF F w E V H T W E A R WMD AE Nov. 2, 1937. w. FERRIS ET AL 2,097,857

HYDRAULIC TRANSMISSION Filed May 26, 1933- Sheets-Sheet s pressor INVENTUH'S WALTER FERRIS JAMES K-DEIUGLAS EEIRGE H-.FDEIAN ATTUHNFY Nov. 2, 1937.

' w. FERQRIS ET, AL

HYDRAULIC TRANSMISS ION Filed May 26, 1933 7 Sheets-Sheet 4 IN'VENTEIFPS WALTER' FERRIS JAMESK-DULIGLAS GEDRBE H-FEIBIAN ATTORNEY.

Nov. 2, 1937. w. FERRIS' ET AL 2,097,857

' HYDRAULIC TRANMISSION Filed May 26, 1933 7 Sheets-Sheet 5 INVENTURS YVVALTERZ FERRPS JAMES K DDUELAS GEEIRBE H RNEY.

w. FERRIS ET AL HYDRAULIC TRANSMISSION NovQZ, 1937.

Filed May 26, 1933 7 Sheets-Sheet 6 I compressor Nov. 2, 1937; w. FERRIS ET AL 2,097,357

HYDRAULIC 'rmsnssron Filed May 26, 1933 7 Sheets-Sheet 7 INVENTURS WALTER" F'ERH'IS JAMES K.Duuxs| As GEDREE H FDBIAN B ATTFIRNEY.

Patented Nov. 2, 1937 Walter Ferris and James K. Douglas, "Milwaukee, and George H. Fobian, West Allis, Wis., assignors to The OiIgear-Company', Mil? waukee, Wis., a corporation of Wisconsin Application May 26.1933, Serial No. 613,013 14 Claims. oi. 257-4) This invention relates to 'a hydraulic transmission which is particularly adapted for driving the refrigerating apparatus employed to cool the interior of .a vehicle, such as a refrigerator) 5 car or a railway passenger car.

The power for driving the refrigerating apparatus of a railway car is derived from the car wheels which rotate at widely varying speeds depending upon the speed at which the car is traveling, but the refrigerating machinery should be driven at a substantially constant speed or at speeds which-vary through a very narrow range.

A refrigerator car may remain on a side track or in a railway yard during a time when its 0 interior should be either cooled or heated to provide comfort for the occupants of a passenger car or to preserve the contents of a refrigerator car. A

The present invention has as an object to provide a hydraulic transmission which will. drive the refrigerating apparatus of a vehicle at a substantially constant speed within a wide range I of vehicle speeds.

' Another objectis to provide a hydraulic transmission which will drive the refrigerating apparatus of a. vehicle in a given direction irrespective of the direction of vehicle movement.

Another object is to-provide a hydraulic trans-. mission which will either generate heat to heat a vehicle or drive a refrigerating apparatus to cool the vehicle. y r

Another object is to translate power derived either from the wheels of. the moving vehicle or from a stationary electric circuit into energy for heating the vehicle or for driving the refrigerating apparatus thereof."

Another object isto provide a'hydraulic'trans mission of this character which is highly efiicient in operation.

40 I Another object is to provide the refrigerating apparatus of a vehicle with a drive-.which is economical I I drives.

A transmission constructed in accordance with the present invention has the advantage of being fully automatic in operation and susceptible of close adjustment and control.

Other objectsand advantages will appear from the description hereinafter given of a transmission in which the invention is embodied.

According to the invention in a general aspect and as ordinarily embodied in practice, the trans mission .is provided with a hydraulic motor for I driving the refrigerating apparatus of a vehicle, a pump which is driven from the wheels of the to manufacture relative to other vehicle at speeds varying in accordance with the vehicle speed. means for directing liquid fromthe pump to the. motor to drive the same, and

means for varying the relative displacements of the pump and the motor in accordance with 5 variations in vehicle speed to thereby enable the motor to drive the refrigerating apparatus at a substantially constant speed during a wide variation in the speed of the vehicle.

According to-the invention inanother aspect, 10v means are provided for directing liquid from the pump to the motor to drive the'same in. a given direction irrespective of the direction of pump actuation. According to the invention in-another aspect, 15

an electric motor provides the motive power when thevehicleis stationary; r The invention is exemplified by the' transmission shown schematically in the accompanying drawings in which the views are as follows; -20

Fig. 1 is aside view of apart of .a'railway refrigerator car. to which the invention has been applied. 1 A

Fi 2 is a. plan at-aka on the line '2 2- ofFig.1.

, Fig. -3 is a schematic drawing of the hydraulic and electric circuits emplo'yedin one embodiment of the invention and shows the various parts thereof in the positions occupied when the car is in motion andthe'temperature of the car is 30' not being corrected.

Fig. 4 is a viewsimilar to Fig. 3 but showing the parts in the positions occupied when'the car' is in motion and the interior-thereof is, being cooled.

heated.

Fig. 6 isa view similar to Fig. 3 butslio'wing the 40 parts in the positions occupied-when the car is. 1 stationary and the interior thereof is being cooled.

Fig. 7 is a schematic drawing of a modification of the apparatus shown in liig. 3 and shows the parts in the positions occupied when'the car is 45 stationary and the interior thereof is being heated.

Fig. 81s a viewsimilar to Fig. '7 but showing the parts in the positions occupied when the car' is in motion and the interior thereof is being 50 heated. I

Figures-19.11112. The car isprovided with refrigerating "ap- ,v

paratus of which only i :rcompressor 'I and-a cooling coil 2 are shown for-the reason that such 55- 35" Fig. 5 is a view similar to Fig.3 butj'showing the parts in the positions occupied when the car is in motion and the-interior thereof is beings apparatus is well known and of itself forms no part of the present invention.

The coil 2 is arranged withinthe body3 .of the ear, and the compressor I is arranged within a closed housing 4' which is carried by the body 3 upon the underside thereof and encloses parts of the refrigerating apparatus and thehydraulic transmission to protect the same from dust and When the caris stationary, the compressor i may be driven by an electric motor 5 and, when the car is in motion, it may be driven by a hydraulic motor' 6 (Figs. 3-8) which is driven by liquid supplied theretofrom a variable displacement pump I (Figs. 3-8).

The hydraulic motor 6 and the pump 1 are shown separated in Figs. 3 to 8 but, in practice,

they arearranged within a, single transmission casing 3'which is-enclosed bythe' housing' i and has a valve casing 9 attached thereto -as shown inFi g.2. I

The valve casing Scontains certain valves which are shown schematically in Figs. 3 to 8 and which control the flow of liquid from the pump I to the motor-.6 and from the pump I or the motor 3 to a heating coil-I which is arranged within the car body 3.-

When the car is moved in either direction, the

' pump 1 is driven from the car axlejll through a flexible drive which automatically compensates for variations -.in the relative positions in the pump I and the axle II) 4 As shown, the pump I has a pulley l2 fixed upon the outer end of its drive shaft l3 and connected by atexrope drive I l to a pulley J which is arranged betweentwo stationary bearings I6 fixed to the car. body, upon the underside thereof.

The pulley I5 is fixed upon a countershait II which is journaled in the lower ends of the bear- .in'gs I3 and connected toa swinging shaft I8 by a universail joi'nt'lS.

The swinging shaft .58 is journaled in the lower endsof twopivoted'bearings 23 and has a pulley 2| fixed thereon between the bearings and connected by a belt 22 to a pulley 23 which is ar-' ranged upon the axle II and fixed for rotation therewith. Y

Each bearing 20 is-plvoted at its upper end to the underside, of the car body and has its lower end urged by a spring 24 toward the housing 3 to keep the belt 22 tight.

Movementof .the bearings 23 in either direction is limited by a stop rod 25 which has one of its endsattached to thehousing 4 and its other end provided with twostops 28 arranged upon either side of a, yoke 21 which connects the lower ends ofthe bearings 23 to each-other; f

The pump I is'thus positively driven wheneverthe car is in motion, and it will deliver liquid to the hydraulic motor 6 or to the-heating coil I3 01' its output will be bypassed'depending upon the positions of the several valves, as will be presently-explained, The valves are automatically controlled in; the usual, manner by electric thermostats which i are supplied with electric energy fromastorage battery'23 (Figs. 3-8).

The battery 28 is kept charged by a generator.

' 29 arranged' withinthe'housing 4 and connected by "a belt30 the-electric motor 5 which is connected b gearing 3| '(Figs. 3-3) to the hydraulic motor 6. Ccnsequently, the generator is driven w henever the electric motor 5 is being currentsupplied from an external c'uit, 'orwhenever, the hydraulic the'pump I at which it ra e Y tati i rr meters driven by time the electric motor 5 spins idly and functions as a flywheel. 1

If it is desired that the apparatus be capable of heating the car when it is stationary, a magnetic' clutch 32 is connected between the compressor i and the gearing 3i but,if standby heating is not desired,the clutch 32 is omitted.

Figures 3-6. The aparatus shown schematically in these figures is adapted to either cool or heat the car when the pump 7 is being driven from the axle I I or to cool the car when the electric motor 5 is energized by current from an external stationary circuit. v

When the pump I is being driven, it discharges liquid into either a channel 33 or a channel 33 and receives liquid through either the channel 33 or the'channel 33, depending upon the direction the car is moving and, consequently, the direction in which the pump is being driven.

The channels 33 and 34 communicate, respectively, through two check valves 35 and 33 with the channel 34 but prevent it from flowing in the opposite direction.'

When the pump I is driven in one direction, it

delivers liquid to an external circuit through the channel 33, the check valve 35 and the discharge channel 37, and the check valves 36 and 38 prevent the liquid from entering the channels 34 or 40. Liquid is returned from the circuit to the pump through the return channel ii, the-intake channel the check valve 39 and the channel 34.

When the pump is driven in the opposite dithrough the channel 34, the check valve and the discharge channel 3?, and the check valves 35 and 39 prevent the liquid from entering the rection, it delivers. liquid to an external circuit channels 33 and 50. Liquid is returned from the circuit to the pump through the return channel 4| the intake channel Ml, the check valve 33 and the channel 33.

The return side of the hydraulic circuit is. kept flooded with liquid under a low pressure by a gear pump 32 which is driven in unison with the variable delivery pump I.

The gear pump AZdraws liquid from a reservoir 33 through a channel 44 or a channel 35 and delivers it into either the channel 45 01 the channel M, depending upon the direction of pump actuation.

The channels 34 and 45 are connected, respectively, through two check valves 46 and 41 to the intake channel 30 and through two check valves 48 and E3 to a suction channel 50 which extends downward into the reservoir 33. These check valves permit liquid to flow from the reservoir 43 to the intake channel 40 but prevent it from flowing in theopposite direction.

' The pressure created by the variable displacement pump 1 is limited by a relief valve 5| which is adjusted-to open at a high pressure, for instance 1500#, and has'its inlet connected by a channel 52 to the discharge channel 31 and its outlet connected to a drain channel 53 which dis chargesinto the reservoir 43. r

, port 6| to the port 58 and permit liquid to escape The pressure created by the gear pump 42 is limited by a relief valve 54 which is adjusted to open at a low pressure, for instance 50#, and has its inlet connected to the intake channel 46 and its outlet connected to the drain channel 53.

The pump I may be any one of the several types, but a pumpwhich is particularly suited for the purpose is disclosed in application Serial No. 662,219 filed March 23, 1933 by Walter Ferris. The gear pump. 42 is ordinarily incorporated in the pump I as substantially a part thereof, but the pump shown in the above application does not have a gear pump incorporated therein. However, the addition of a gear pump to a variable displacement'pump is common practice, as shown by Patent No. 1,753,562 issued April 8, .1930 to John P. Ferris.

The pump urged toward full stroke position by springs 55 and urged toward zero stroke position by a hydraulic motor 56 which is connected by a channel 57 to an admission port 58 formed in the casing of a stroke control valve 59 intermediate the'ends thereof.

I The stroke ofthe pump I is varied in accordance with variations in the pressure prevailing in the channel 51, and this pressure is limited by a relief valve 60 which is adjusted to open at a low pressure, for instance 200#, and has its inlet connected to the channel 51 and its outlet connected to the drain channel 53.

v The stroke control valve 59 has two ports 6| 'and 62 formed'in its casing upon either side of the port 58 and controlled by a plunger 63 which is fitted in the bore of the casing and has a piston arranged upon each of its ends.

When the pump is being driven at a uniform speed, the pistons ofthe plunger 63 have the ad- 'jacent edges thereof substantially in alinement with the'adjacent edges of the ports 6| and 62, and the forces acting upon the ends of the plunger 63' are such that the plunger 63 substantially floats in this position so that a variation in the force acting upon one of its ends will destroy the equilibrium of the plunger and cause it to uncover one of the ports and completeliquid to flow to the motor 56 to thereby decrease the stroke of the pump, and movement of the plunger 63 in the opposite direction will open the from the motor 56 to thereby increase the stroke of. the pump, the port 6| being connected to the drain channel 53 through a choke 64 which limits the rate at which the motor 56 may move the .stroke changing element of the pump I (and thereby prevents it from-hunting.

The plunger 63 is urged toward the leftin re-.

'spect to Fig. 3 by the fluid pressure prevailing in the return channel 4|, which has its other end connected to .the casing of the valve 59 at the I right end thereof, and by a helicalcompresslon spring 65 which is arranged within the casing of the valve 59 and has its tension adjusted by a screw 66.

The plunger 63 is urged toward the right by 1 the fluid pressure prevailing in the return channel Which is connected at one of its ends to the left end of thevalve casingand is connected intermediate its ends through an orifice or choke thereof. I I

Liquid returned from the hydraulic circuit to 6,8 to the return channel 4| intermediate the ends I has its stroke changing element the pump I flows from the channel 61 to the channel 4| through the orifice 68 which causes a drop in pressure between the channel 61 and the channel 4|, and this drop in pressure varies in accordance with variations in the velocity of the liquid. V

- The orifice 68 is so adjusted or proportioned and the spring 65 is so adjusted thatthe forces exerted by the liquid and the spring upon the right end of the plunger 63will just balance the A force exerted by the liquid upon the left end of the plunger 63 when the pump is -delivering liquid at the correct volumetric rate to the hydraulic motor 6 to cause it to drive the compressor I at the correct speed, thereby retaining the valve plunger 63 in its intermediate position and trapping liquid in the motor 56 to holdthe stroke changing element of the pump I in its adjusted position.

The port 62 in the valve 59 is open at all times to the channel 61 through a duct 69 which ex-' tends axially inward from the left end of the it to; reduce the stroke of the pump until the volume of liquid delivered-by the pump is reduced to the correct-rate to produce the correct speed of the compressor I.

The output-of the pump I and the speed of the compressor I-are thus maintained at substantially' uniform and constant rates at any car speed wihin a wide range of car speeds.

I The pump control mechanism described abov is not claimed herein for the reason that it is described and claimed in application Serial No.

The liquid discharged by the pump I flows through the discharge channel 37 which has its port I6 formed in the casing of a valve II which controls the delivery of liquid to the heating coil I 6.

The port I0 is normally open to an annular port I4 formed in the casing of a valve I5 which controls the operation of the hydraulic motor 6. The port I4 is connected by a channel I6 to open to an annular port 11 to which the outer or inlet end of the return channel 61 is connected.

677,546 filed June 26, 1933 by James K. Douglas.

-outer or discharge end connected to an annular v 'port I2 which is arranged at the left of theport I III and connected by a channel I3 to an annular The valve II has a annular port I8 formed v therein at the right of the port I0 and connected 1 by a pipe 19 to one end of the heating can In theother end of which is connected by a pipe to the return channel 61 intermediate the ends thereof. Y The coil I0 may have its passageway sufficiently restricted throughout the length thereof to cause trolled byits plunger 82 which is urged against the left. end of the valve casing by a helical compression spring 83 arranged in the right end of v the valve casing. V

. 55 the inlet of the hydraulic motor 6 and is normally I nel 93 to the port Win the valve I5, and the drain port 08 is connected to a drain channel 95 which The plunger 82 is adapted to be moved toward the right by liquid supplied through a channel 85 which connects the left end of the valve casing to an annular port 35 formed in the casing of a pilot valve 86 between an admission port 87 and a drain port 88.

The flow of liquid through the pilot valve 36 is controlled by its plunger 89 which normally blocks the port 81 and is urged against the left end of the valve casing by a helical compression spring 30 arranged in the right end of the valve casing. The plunger 89 is adapted to be moved toward the right by a solenoid 9i which has its core connected thereto by a valve stem 92.

The admission port 81 is connected by a chanis also connected to both ends of the pilot valve casing and'to the right end of the casing of the valve II .to permit the plungers 82 and 89' to be freely moved therein.

The flow of liquid through the valve I5 is controlled by its plunger 95 which controls communication between the port I1 and the port I4 and between a port I1 and the port 96 which is connected by a channel 91 to the outlet of the hydraulic motor 6. r

The plunger 95 is urged against the leit end of the valve casing by a helical compression spring- 98 arranged in the right end of the valve casing,

and it is adapted to be urged to the right by liquid supplied through a channel 99 which connects the left end of the valve casing to a port I00 formed in the casing of a pilot valve IOI between an admission port I02 anda drain port I03.

The flow of liquid-through the pilot valve IOI is controlled by a plunger I04 which normally blocks the port I02 and is urged against the left end'oi' the valve casing by a helical compression spring I05 arranged in theright end of the valve. casing. The plunger I04 is adapted to be moved to the right by a solenoid I05 which has its core connected thereto by a valve stem I01.

The admission port I02 has the channel 93 connected thereto, and the drain port I03 is connected to a drain channel I08 which discharges into the drain channel 53 andis'connected to both ends of the pilot valve casing -to permit the plunger ltd to move freelytherein.

The pilot valve IOI has the drain channel 94 connected to the left end of its casing to permit it to discharge therethrough into the drain chan-' nels E08 and 53, and the drain channel 94 is connected by a channel I09 to the right endof the casing of the valve I5 to permit the plunger 95 to move freely therein.

' v solenoid 9I will be energlzed and move the plunger 89 of the pilot valve ,86 to the right to the' The solenoid 9| has one end of its windings connected by a conductor IIO to one terminal of a switch III the other terminal of which is connected by a conductor H2 direct to one terminal of the generator 29 and through a manual switch 3 to one terminal of the battery 28.

The other terminals of the battery 28 and the generator 29 are connected through conductors I I4 and I I5 to the other end of the winding of the solenoid 9| and to one end of the winding of the solenoid I06 the other end of which-is connected to a conductor I It to one terminal of a switch I I1 which has its other terminal connectedto the conductor H2. j

When the switches III and I I3 are closed, the

position shown in Fig. 5. When the switches II! and [I3 are closed, the solenoid I06 will be ener- -a predetermined closes the switch -I I1 and keeps. it closed until the 0 temperature within the can drops to ,a predeter-- mined degree.

. discharges valve 36, depending upon mined degrees of temperature.

. When the temperature within the car drops below a predetermined minimum, the thermostat I I8 closes the switch I I I and keeps it closed until the temperature within the car rises to a predetermined degree.

When the'temperaturewithin the car rises above maximum, the thermostat II 9 The thermostat II9 also operates a switch I20 which controls the flow of current between the.

electric motor 5 and an external electric circuit which ,is representedby a flexible twin-conductor i2I having a connector I22 arranged upon the end thereof.; e connector I22 is adapted to be connected to a receptacle I23 which is carried by the car body and connected to one terminal of the motor .5 by a conductor I24 and to' one terminal of the switch I20'by a conductor I25. The otheriterminals of the motor 5 and the switch I20 are connected to eachother by a conductor I26. When the connector I22 is insertedin the receptacle I23 and the switch I20 is closed-the motor 5 will be energized and drive the hydraulic motor I5 which will function as a pump and draw liquid through the channel I6 and discharge, it

into the channel 91. Pressure created by the motor Swhen functioning as a pump is limited by a relief valve I21 which is connected to the channel 91 and discharges into the drain channel 53.

When the electric motor 5 and the pumps I and 62 are idie,'as when the car is stationary and the motor 5 is not connected to an externalelectric circuit, the parts assume the positions shown in Fig. 3 with the exception of the p1ung-.

er 63 of thestr'oke control 'valve'59 which is in the position shown inFig. 6.

Figure 3.

This figureshowsthe positions assumed by the several parts when the car isrunning and the temperature of the car' is either within the prescribed limits or is not being controlled due'to the manual switch I I3 being open.

Under either of these conditions,

liquidinto-the discharge channel 3! either through valve 35 or through the channel 34 and the check the direction in which the car is moving.

The liquid flows through the channel 31; the

valve II via the ports wand I2, the channel I3, the valve i5 via the ports I4 and I1 and returns to the pump through the return channel 61, the choke or orifice 68, the return channel 4|,

7 the intake channel. 40 and either through thecheck valve 39 and the channel 34 or through the check valve 33 and the channel -33.

As long as the car moves at a slow speed so that the pump. I is driven at slowspeed, the plunger 63 of the valve 59 remainsjin the er-- tion shown in Fig. 6 but, when the car speed increases above acertain' and thereby the channel 33 and the check thepump I nel 16 to the motor 6 and drive it. Liquid disto the right, as previously explained, and liquid from the channel 61 flows through the duct 66, the ports 62 and 58 and the channel 51 to the motor 56 and operates it to reduce the stroke of the pump to maintain the pump output at a predetermined volumetric rate.

The gear pump 42 draws liquid from the reservoir 43 through the suction channel 50 and through either the check valve 48 and the chanme] 44 or through the check valve 49 and the channel 45. and discharges it into the intake channel 40 either through the channel 44 and the check valve 46 or through the channel 45- and the check valve 41, depending upon the di rection in which the car is moving.

Substantially all of the liquid discharged by the gear pump at this time is exhausted through the relief valve 54 which causes the gear pump to maintain a low pressure in the channel 40 and to tend to deliver liquid through the check valve 38 or the check valve 39 to the intake of the pump 1 to maintain pressure therein and to compensate for leakage losses.

The gear pump also maintains pressure in the return channel 4| which requires the pump 1 to create pressure in the channels 31, 13 and 61, and this pressure extends through the channel 93 to the ports 81 and I02 which are blocked at this time by the plungers 80 and I04, respectively. This pressure also extends through the channel 16 to the hydraulic motor 6 but is insuflicient to drive it. t

Figure 4.

If-the temperature within the car rises above a predetermined maximum, the thermostat H9 closes the switch II1 to energize the solenoid I06 which moves the .pilot valve plunger I 04 toward the right. The thermostat 9 also closes the switch I20 but this has no effect upon the electric motor 5 since the switch 20 is not connected to an electric circuit at this time.

Moving the pilot valve plunger I04 toward the right blocks the drain port I03 and opens the admission port I02 to the port I00, thereby per-. mitting liquid to flow from the channel 03 through the pilot valve casing and the channel 50 to the left end of the casing of the valve 15 and move its plunger 95 toward the right to close communication between the port 11 and I the port 14 and to open communication between the port' 11 and the port 96.

Liquid from the pump 1 may now flow through the discharge channel 31, the valve 1|, the channel 13, the port 14 in the valve 15 and the chancharged from the mot0r.6 flows through the channel 91, the valve 15 via the ports 96 and 11 into the return channel 61;

- The motor 6 drivesthe compressor I, and the refrigerating apparatus operates and cools the 'car until the temperature therein drops below a predetermined degree at which time the thermostat 3 opens the switch II1 to deenergize the solenoid I06 and then the several parts assume the positions shown in Fig. .3.

If the carspeed changes during operation of the motor 6, the stroke control apparatus func- -tions. to vary the stroke of thepump 1 inversely proportional to the variation in car speed so that the pump 1 delivers liquid at a substantially constantrate and thereby'drives the motor. 6,to operate the compressor I at a-speed which remains substantially constant within a wide range of car Figure 5. v If the car travels through an area of low outside temperatures so that its internal temperature drops below a predetermined minimum, the thermostat 8 closes the switch III to energize the solenoid 9| which moves the pilot valve plunger 86 to the right to block the drain port 88 and open the admission port 81 to the port 05 and permit liquid to flow from,the channel93 through the pilot valve casing and the channel 84 to the left end of the casing of the valve 1| and move its plunger 32 toward the right to close communication between the port 10 and the port 12 and to open communication 10 and the port 18.

Liquid from the pump 1 may now flow through the channel 31 and through the valve 1| via the ports 10 and 18 into the pipe 19and be forced through the choke 8| and the heating coil M to heat the car. Liquid is discharged from the coil l0 through the pipe 80 into the return pipe 61.

' The apparatus functions in this manner until the temperature within the car rises to a predetermined degree and then the thermostat 8 opens the switch I to deenergize the solenoid 0|. The several shown in Fig. 3.

Figure 6.

If the car is stationary and the receptacle I23 is connected into an external electric circuit, as by means of the conductor |2| and the connector I22, and if the temperature within the car rises above a predetermined maximum, the thermostat 0 will close the switch I20 to energize the electric motor 5.

The thermostat 9 also closes the switch I I1 and thereby energizes the solenoid I06 which moves the pilot valve plunger I04 toward the right but, since there is no pressure at this time in the channel 93,the spring 98 continues to hold the plunger 95 of the valve against the left end of the valve casing.

The electric motor 6 drives the compressor I, to cause the refrigerating apparatus to cool the car, and at the same time it drives the hydraulic motor 6 which will function as a pump and draw liquid from the reservoir 43 through the path of least resistance which would probably be the channel 50, the check valve 48, the channel 44, the check valve 46, the channel 40, the check valve 39, the channel 34, the check valve 36, the channel 31, the valve 1|, the channel 13, the valve 15 and the channel 16. Themotor will discharge liquid through the channel 91, the valve 15, the channels I09 and 34, the valve IM and the channels I03 and 53 into the reservoir43.

Since these passages are all substantially free,

' the liquid will circulate freely and but little power same as the apparatus shown in Figs. 3 to 6 except that it has been modified to permit'liquid to be directed from the motor 6 through the heating between the port parts then assume the positions coil I6 to heat the interior of the car when the car is stationary and the electric motor is driven by power supplied from a stationary electric circuit.

In this form of the apparatus, the channel I09 is connected to a port I38 in the valve H instead of being connected to the drain channel 94, the port 96 in the valve 15 is connected through a check valve I3I to the discharge pipe 31, the pipe 88 connects the discharge end of the heating coil II] to a magnetically operated auxiliary valve I32 instead of connecting it to the return pipe 61, as in Figs. 3 to 6, and the magnetic clutch 32 is connected between the gearing 3i and the compressor I.

Since there is no fluid pressure available to operate'the valve 1I hydraulically when the car is stationary, this valve is operated by a solenoid I33 which has its core connected to the plunger 82 of the valve 1I by a valve stem I34. A J

The solenoid I33 has one end of its winding connected by a conductor. I35 to the conductor I24 and the other end thereof connected by a conductor I36 to one terminal of a switch I31 which is operated by the solenoid H8 and has its other terminal connected to the conductor I25. The thermostat II8 also operates a switch I38 which has one of its terminals connected to the conductor I25 and its other terminal connected by a conductor I39 to the conductor I26. When the receptacle I23 is connected into an electric circuit and the switches I31 and I38 are closed, the electric motor 5 will be operated and the solenoid I33, will be energized and move the plunger 82 of the valve 1| toward the right.

The channelIiIl is connected to the auxiliary valve I32 in communication with a port I48 which is arranged between two ports I4 I and I42 formed in the valve casing. The port I is connected by a channel I43 to the return channel 61, and the port I42 is connected to a drain channel I44 which discharges into the drain channel 53 and;

is also connected to both ends of the valve casing.

The now of liquid through the auxiliary valve I32 is controlled by its plunger I45 which is urged toward the left by a spring I46 and adapted to be moved toward the right by a solenoid I41 which has its core connected thereto by a valve stem I48. 3

The solenoid I41 has one end of its winding connected to the conductor- I35-and the other end thereof connected to'the conductor I36 so that,

tor I36 by a conductor I 56 so that it may be enerwhen the solenoid I33 is energized, the solenoid I41 will also be energized and the valve plungers 82 and I45 will be moved toward the right at substantially the same time.

The switch I31 also controls. the magnetic clutch 32 which has one of its terminals connected to the conductor I24 by a conductor I49 and its other terminal connected to the conducgized in unison with the solenoids I33 and I41. In order that the motor 6 may draw liquid from the reservoir 43, the return channel 61 is connected intermediate its ends toa suction channel I5I which extends into thereservoirfl'and has a check valve I52 arranged therein to permit liquid to be drawn from the reservoir into the return channel 61 but prevent it from flowing in the opposite direction. I

Figure'1. f When the car is stationary, the receptacle I23 connected into an electric circuit and the temperature within the car falls below a predetermined minimum, the thermostat II8 will close the switches III, I 31 and I38.

Closing the switch III will cause thesolenoid 8I to be energized and move the pilot valve plunger 89 toward the right but, since there is no pressure in the channel 93, this movementwf the plunger 89 will have no effect upon the valve' plunger 82.

Closing the switch I31 will cause the magnetic clutch 32 to be energized and disconnect the compressor I from the gearing 3| and also cause the solenoids I33 and I41 to be energized and move the valve plungers 82 and I45 toward the right to the positions shown.

Closing the switch I38 will cause the electric motor 5 to be energized and drive the hydraulic motor 6 which will function as a pump, the compressor I remaining idle due to the clutch 32 being disengaged. I

The motor 6 will draw liquid from the reservoir 43 through the channels I5I and 61, the valve 15 and the channel 16 and discharge the channel 91, the port 86 in the valve 15, the check-valve I3I, the outer end of the channel 31, the valve H, the pipe 19 and the choke 8| into the coil III to heat the car. The liquid discharged from the coil III will flow through the pipe 88, the valve I32 and the channels I44 and 53 to the reservoir 43.

Pressure created by the motor 8 extends throughout the length of the channel 31 but the liquid is prevented from escaping from the inner end thereof by the check valves 35 and 36 and by the relief. valve 5I. Pressure also extends through the right end of the valve 15 to the channel I89 but the liquid is prevented from escaping therefrom by the valveplunger 82 which at this time blocks the port I36 in the valve H.-

I When the temperature within the car reaches a predetermined degree, the thermostat II8 will open the switches -I I I, I31 and I38 to permit the 3, and the spring I46 to return the valve plunger I45 to its normal position as shown in Fig. 8.

Figure. 8.

This figure shows the modified apparatus with I I41 are not energized due to the fact that the receptacle I23 is not connected into an external electric circuit.

Closing the switch III, however, causes the solenoid 8| to be energized and move the plunger.

it throughvalve springs to return the valve plungers 82; and 89 to their normal positions, as shown in Fig.

86 of the pilot valve toward the right to open,

the port 81 to the port 85 as in Fig. 5.

Since the pumps 1 and 42 are being driven from the car axle'and creating pressure in the channel 93, liquid flows through the pilot valve.v

86 and the channel 84 to the left end of the valve 1! and moves its plunger 82 toward the right to open the port 18 to the port ports 12 and I30.

The liquid discharged by the pump 1 into the 18 and to block the channel 31 flows through the valve H, the pipe 18 and the choke 8| into the coil I8 to heat the car, and liquid discharged from the coil III flows through the channel 86, the ports I40 and MI in the valve I32, the channels I43 and 81 and the orifice 68 to the return channel 4I.

Whenthe temperature of the car reaches predetermined degree, the thermostat III opens the'switch l i i to deenergize the solenoid 9i and V permit the valve plungers 89 and 82 to be returned to the positions shown in Fig. 3. The

output of the pump 1 is then bypassed as in that figure.

Since the auxiliary valve I32 is employed solely for directing liquid from the discharge end of,

the coil ID to either the reservoir 43 or to the intake the pump 7, the apparatus shown in Figs. 7 and 8 functions to cool the car in exactly the same manner as the apparatus shown in Figs.

The invention herein set forth is susceptible ofv various modifications and adaptations without departing from the scope thereof as hereafter claimed.

The invention is hereby claimed as follows: 1. The combination, with a vehicle and apparatus carried by said vehicle, of a pump driven by motion imparted thereto from said vehicle, a hydraulic motor driven by liquid supplied thereto by said pump for driving said apparatus, fluid channels connecting said pump and said motor and forming therewith a hydraulic circuit, and means responsive to a drop in pressure between two parts of said circuit for maintaining the speed of said motor substantially constant within a wide range of speeds of said vehicle tothereby operate said apparatus at a substantially constant speed at 'any vehicle speed within said range. t

2. The combination, with a vehicle and apparatus carried by said vehicle, of a variable displacement pump driven by motion imparted thereto from said vehicle, a hydraulic motor driven by liquid supplied thereto by said pump for driving said apparatus, and fiuid actuated means responsive to variations in the velocity of the liquid circulated by said pump for varying pump displacement inversely to said variations in velocity to thereby enable said motor to operate said apparatus at a substantially constant speed at any vehicle speed within a wide range of vehicle speeds.

3. The combination, with a wheeled vehicle and apparatus carried by said vehicle, of a hydraulic motor for driving said apparatus, a pump for supplying liquid to said motor to drive the same, a drive connecting said pump to a wheel of said vehicle for driving said pump'from said wheel, fluid channels connecting said pump and said motor and forming therewith a hydraulic circuit, and'means responsive to a drop in pressure between two parts of said circuit for varying the ratio between the displacements of said pump and said motor in accordance with variations in the speed of said wheel to thereby enable said motor to drive said apparatus at a substantially constant speed at any Wheel speedwithin a wide range of wheel speeds.

4. The combination, with a wheeled vehicle and apparatus carried by said vehicle, of a hydraulic motor for driving said apparatus, a variable displacement pump for supplying liquid to said motor to drive the same, a drive connecting said pump to a wheel of said vehicle for driving said pump from said wheel, fiuid channels connecting said pump and said motor and forming therewith a hydraulic circuit, and means responsive to a drop in pressure between two parts of said circuit for varying pump displacement inverLsel'y to variations in the speed of said wheel to h ereby enable said motor to drive said appara'tus at a substantially constant speed at any wheel speed within wide range of wheel speeds.

draulic motor for driving said apparatus, a pump for supplying liquid to-said motor to drive the same, a drive connecting said pump to a wheel of said vehicle for driving said pump from said wheel, and fluid actuated means responsive to variations inthe velocity of the liquid circulated by said pump for varying the ratio between the displacements of said pump and said motor in accordance with variations in the speed of said wheel to thereby enable said motor to drive said apparatus at a substantially constant speed at any wheel speed within a wide range of wheel speeds.

. 6. The combination with a wheeled vehicle and air conditioning apparatus carried by said vehicle, of a hydraulic motor for driving said apparatus, a pump driven from the wheel of said vehicle 'and delivering liquid in either of two opposite directions in accordance with the direction of ro-' tation of saidwheel, means for directing liquid from said pump to said motor to drive the same in a given direction irrespective of the direction paratus, a variable displacement pump driven from a wheel of said vehicle and delivering liquid in either of two opposite directions in accordance with the direction of rotation of said wheel, means for directing liquid from saidfpump to said motor to drive the same in a givendirection irrespective of the directionof pump delivery, and means for varying pump displacement inversely to variations in the speed of said wheel to thereby enable said motor to drive said apparatus at a substantially constant speed at any wheel speed withina wide range of wheel speeds.

8. The combination with a wheeled vehicle and air conditioning apparatus carried by said vehicle, of a hydraulic motor for driving said apparatus, a variable displacement pump driven from a wheel of said vehicle and delivering liquid in either of two opposite directions in accordance with the direction of rotation of said wheel, means for directing liquid from said pump to said motor to drive the same in a given direction irrespective of the direction of pump delivery,

and means responsive to variations in the velocity of the liquid circulated by said pump for varying pump displacement inversely to variations in the speed of said wheel to thereby enable said motor to drive said apparatus at a substantially constant speed at any wheel speed within a wide "range of wheel speeds.

9. The-combination, with a vehicle and air conditioning apparatus carried by said vehicle for cooling the interior thereof, a hydraulic motor electric circuit when said vehicle is stationary, and

for cooling the interior thereof, a hydraulic motor .for driving said apparatus,

a heating coil carried bysaid vehicle to cause liquid forced therethrough to heat the interior of said vehicle, a pump driven by motion -imparted theretofrom said vehicle for delivering liquid to said motor and said coil selectively, an electric motor for driving said hydraulic motorto cause it to function as a pump, means for connecting said motor into a stationary electric circuit when said vehicle is stationary, fluid connections for enabling said hydraulic motorto circulate liquid through said coil upon being driven by said electric motor, means for diverting from said coil the liquid circulated by said hydraulic motor, and means for connecting said electric motor to said apparatus to drive the same.

11. The combination, with a vehicie and refrigerating apparatus carried by said vehicle, of a'hydraulic motor for driving said apparatus, a pump driven by motion imparted thereto from said vehicle for supplying liquid to said motor to drive the same, a hydraulically operated valve for controlling the delivery of liquid to said motor, a pilot valve for controlling operation of said hydraulically operated valve, and means responsive to variations in the temperature within said vehicle for operating said pilot valve.

12. The combination, with a vehicle and refrigerating apparatus carried by said vehicle, of a hydraulicmot'or for driving said apparatus, a

pump driven by motion imparted thereto from said vehicle for supplying liquid to said motor to drive the same, a hydraulically operated valve for directing liquid from the discharge side of said pump either to said motor orto the return side for controlling said of said pump, a pilot valve for controlling operation of said hydraulically operated valve, and means responsive to variations in the temperature within said vehicle for operating said pilot valve.

13. The combination, with a vehicle and refrigerating apparatus carried by said vehicle, of a hydraulic motor for driving said apparatus, a

pump driven by motionimparted thereto from said vehicle for supplying liquid .to said motor. to drive the same, a hydraulically operated valve for controlling the delivery of liquid to said motor, means including an auxiliary pump; driven by motion imparted thereto from said vehicle for delivering liquid to said hydraulically operated valve to operate the same, a pilot valve for controlling said delivery to thereby control operation of said hydraulically operated valve, and means responsive to variations in the temperature within said vehicle for operating said pilot valve.

14. The combination, with a vehicle and refrigerating apparatus carried by said vehicle, of a hydraulic motor for driving said apparatus, a pump driven by motion imparted thereto from said vehicle for supplying liquid to said motor to drive the same, a hydraulically operated valve for directing liquid from the discharge side of said pump either said pump, means including an auxiliary pump driven by motion imparted thereto from said vehicle for delivering liquid to said hydraulically to said motor or to the return side of operated valve to operate the same, a pilot valve delivery to thereby control operation of said hydraulically operated valve, and means responsive to variations in the temperature within said vehicle for operating said pilot'valve.

WALTER FERRIS. JAMES K. DOUGLAS; GEORGE H. FOBIAN. 

